Casing

ABSTRACT

The invention relates to casings for portable communication devices. The casing is reusable with engines having different processing capabilities.

FIELD OF THE INVENTION

The invention relates to portable communication devices and inparticular to casings for such devices and associated methods.

BACKGROUND OF THE INVENTION

Items of technical equipment are generally bought for theirfunctionality. They are quickly superseded and replaced when a faster,cheaper to operate, smaller, or higher specification alternative isreleased onto the market, the previous model being discarded. The valueof the product to its user is in what it can achieve, and perhaps to anextent the image that attaches to the owner of such an item. As fashionis constantly changing so is the image promoted by owning an individualitem particularly in a fast moving technical area. What may have beenthe height of fashion can swiftly become out moded.

In fast moving technical areas changes are prompted by, amongst otherthings, the requirement to make the product smaller, cheaper, cheaper touse, have greater functionality, make use of emerging technologies ormove with the latest tastes in design.

Generally when a radically new technical product is brought onto themarket, for an initial period the product is elite and expensive.Consequently only limited numbers are produced. In the early years,because of the inherent rarity and the cost of components, there is apropensity to repair as much as possible. Despite the economicrequirement for repair, as soon as a better product is launched, theprevious item is soon obsolete and abandoned. The drive for innovationis the challenge of technical advancement and reduction of costs. Thispattern has been followed with many items including the first colourtelevisions, and the first mobile phones.

In other products such as personal computers upgrading is a possibility,but these upgrades are possible only within carefully predefined limits.The casings being retained as a matter of convenience, it being theretention of the maximum amount of the existing technological hardwarethat drives the changes.

SUMMARY OF THE INVENTION

In accordance with a first aspect of the present invention there isprovided a reusable casing for a personal portable communication devicehaving an operating face carrying a user interface including a pluralityof user input elements, the casing comprising: housing elements defininga cavity for receiving an engine providing the electronic functionalityof the device and a battery for powering the engine; means forreleasably attaching the housing elements one to another to provideaccess to the cavity for receiving the engine; a dividing member fordefining a battery cavity accessible to the user and an engine cavity,the housing member accommodating a connection between the battery andthe engine; mounting means for removably mounting the engine within theengine cavity; and mounting means for removably mounting the batterywithin the battery cavity.

In accordance with a second aspect of the present invention there isprovided a method of modifying a portable communication device having anoperating face carrying a user interface including a plurality of userinput elements and having hardware providing a predetermined processingcapability for supporting electronic functionality of the devicecomprising, removing the engine from the casing; and replacing theengine with another engine having hardware providing a differentpredetermined processing capability.

In accordance with a third aspect of the present invention there isprovided a kit of parts for a reusable portable communication devicecomprising: a casing having an operating face carrying a user interfaceincluding a plurality of user input elements, the casing defining acavity for receiving an engine providing the electronic functionality ofthe device; a first engine including hardware providing a firstpredetermined processing capability for supporting electronicfunctionality of the device; and a second engine including hardwareproviding a second predetermined processing capability for supportingelectronic functionality of the device, the first and secondpredetermined processing capabilities being different.

In accordance with a fourth aspect of the present invention there isprovided use of a casing of a portable communication device having anoperating face carrying a user interface including a plurality of userinput elements and an engine having hardware providing a predeterminedprocessing capability for supporting electronic functionality of thedevice, for housing another engine having hardware defining a differentpredetermined processing capability such that a portable communicationdevice having different operational characteristics is produced.

Devices such as mobile phones and computers have historically beendesigned with the foreknowledge that within periods as short as months,more desirable products with vastly greater functionality will haveovertaken the current models. The devices are accordingly built withthese periods of time in mind.

The various aspects of the present invention result from a radicallydifferent approach to portable communication devices. A reusable casingfor a portable communication device that may be precious, andcustomisable with sentimental value, turns the drives for previousinnovation on their heads. In embodiments of the present invention it isthe casing that is the more enduring element of a technical device.

When creating a reusable casing there are new considerations. Futureengines as yet undesigned need to be accommodated. Future technologiesneed to be factored in. One result is that the engine size will probablynot remain the same. To account for this in embodiments of the presentinvention the means for defining the battery cavity may be replaceableto provide different respective volumes for the battery and enginecavities. In this way as engines with greater functionality becomesmaller a larger battery can be utilised should this be desirable tofill the vacant space and provide a longer battery life.

By displacing the battery and the engine along the length of the casing,for example end-to end, reductions in the size of the engine can bedirectly translated into an increase in size for the battery. Inconventional devices where the engine and battery are back to back, thisdirect correspondence does not occur as the battery size is determinedby the casing itself rather than the engine size.

The battery cavity is desirably accessible to a user for replacement ofa battery.

The casing in embodiments of the invention will be the most enduringfeature of the device. It will perhaps out live a succession of engines.The display may be a replaceable module as is the engine and thebattery. Alternatively the display may be one of the enduring elementsof the design.

In order to be flexible enough for future developments the casing may beprovided with external connectors allowing for greater capability thanis provided for by the functionality of a current engine. This allowshigher data capacity, for example, to be provided in the future when theprocessing capability of the engines increases. This may mean that oneor more of the electrical connectors provided on the casing is notarranged to convey signals. In the interim the connector could be usedfor another purpose.

The casing may be a conventional one part casing or a clam shell, orother two or more part arrangement, where the user input elements orkeys may be located on a different face to a display. In such two partarrangements generally respective casing portions are fixed such thatone is movable relative to the other. The movement may be rotational orlateral.

When a casing is to be reusable it can be made from more valuablematerials as these will not be redundant and cast aside when the nextbest technology comes along. A vast range of materials become availablefor customisation of elements of the device in fact there are virtuallyno bounds. Embodiments of the invention may use precious and semiprecious materials including gem stones, other jewels and minerals,metals including those ranging from gold, silver, and platinum throughto alloys such as steel. Materials such as ceramics in their variousforms are also available for use in embodiments of the invention, thebrittle nature of these materials, being able to be accommodated by thedesign of some embodiments. In addition, materials not generallyconsidered in the context of technological devices, such as skins,leather being a particular example and wood and similar materials canalso be utilised in embodiments of the invention.

As well as the materials themselves individual elements can becustomised with surface decoration that could include veneers of desiredmaterials on plastic or other subframes. The elements could haveinstead, or in addition, surface texture provided by a particular finishor an engraving or encrustation with gems or other stones or materials.

BRIEF DESCRIPTION OF THE DRAWINGS.

Embodiments of the invention will now be described in more detail withreference to FIGS. 1 to 21 of the accompanying drawings of which:

FIG. 1 is a perspective view of a communication device showing oneembodiment of the invention;

FIG. 2 shows front, rear, sides and top views of the communicationdevice of FIG. 1;

FIG. 3 is a schematic representation of a communication device suitablefor embodiments of the present invention;

FIG. 4 is an exploded view of the face of a communication device of oneembodiment of the invention without keys;

FIG. 5 is a view of one layer of a light guide;

FIGS. 6 a and 6 b are sections through the communication device of FIG.1 in the display region;

FIG. 7 is a perspective view of a side frame element and located railsfor constructing a casing

FIG. 8 is a perspective view of the rear of the device with the batterycover removed;

FIGS. 9 a and 9 b are sections through the communication device of FIG.1 in the battery region;

FIG. 10 is a perspective view of the rear of the device with the batterycover in place;

FIGS. 11 a and 11 b are sections showing other embodiments of theinvention;

FIG. 12 is a perspective view of part of the input region of the deviceillustrating the location of legends associated with keys;

FIG. 13 a longitudinal section through the communication device;

FIG. 14 is a schematic section through the light guide illustrating thesurfaces available for carrying the legends;

FIGS. 15 and 16 are perspective views of a partially constructed inputregion of the device;

FIG. 17 is a perspective view of keys of the device including theiractuation mechanisms;

FIG. 18 illustrates some of the keys illustrated in FIG. 17, with thekey tips removed;

FIGS. 19 a and 19 b are front and rear perspective views of the outershell of a bezel respectively;

FIGS. 20 a and 20 b are a graph showing force against distance for a keysuch as that illustrated in FIGS. 17 and 18, and a conventional keyusing a dome respectively; and

FIG. 21 is a bottom plan view of the device of FIG. 1 (with the chinface protector omitted).

DETAILED DESCRIPTION

Embodiments of the invention will be described in greater detail belowwith exemplary materials being given for some specific or individualelements of the device. Where a material or veneer is discussed inrelation to an element, the particular character of the elementdescribed is one of many or several that may be provided as options to aparty commissioning a personalised device in accordance with theinvention. In addition the exact material or surface decoration of theelement could be individually commissioned.

The embodiment illustrated in FIG. 1 is a handheld communication device1 with a precious retainable casing 2. The casing 2 of the device hasbeen designed to be customisable to individual taste with preciousmaterials. To enable individual devices to be created, the number ofexternal parts that the casing is formed from is relatively large incontrast to existing communication devices.

The casing 2 has an optically permeable front face 3 providing aseamless transition from a display region 4 to an input region 5 thatincludes a key array 6. The key array 6 includes a first group ofalphanumeric keys 7, for entering telephone numbers, writing textmessages (SMS), writing names (associated with phone numbers), etc. Eachof the twelve alphanumeric keys 7 is provided with a figure “0-9” or asign “#” or “*”, respectively. In an alpha mode each key is associatedwith a number of letters and special signs used in text editing. The keyarray 6 additionally comprises two soft keys 8, 9, two call handlingkeys 10, 11, two scroll keys 12, and an on/off key 13.

The functionality of the soft keys 8, 9 may depend on the state of thecommunication device and position within the menu accessed using thescroll keys 12. The current functionality of the soft keys 8, 9 can beshown in separate fields in the display region 4 just above therespective keys 8, 9.

The two call handling keys 10, 11 are used for establishing a call or aconference call, terminating a call or rejecting an incoming call.

The two direction keys or scroll keys 12, in the handset illustrated areplaced centrally on the front surface of the communication devicebetween the display region 4 and the group of alphanumeric keys 7perform a scrolling function.

The seamless face 3 is formed from an optically seamless light guide 14providing light to illuminate the display region 4 and key legends 15located on the light guide 14 and associated with individual keys of thekey array 6.

The front face 3 is overlaid with a pillow 16 providing apertures 17 tochannel sound from a loud speaker 18 and providing an appropriate feelfor an element of the device that will be located close to the user'sear. The front face 3 is surrounded by a bezel 19 that can be made froma precious metal. This acts to protect the edges of the light guide 14and can help in some embodiments in securing the elements of the casing2 together.

The keys of the key array in this particular embodiment are arranged toprovide particular sensory guidance to the user. Aspects of the designalso allow the light guide 14 to be made from a wide range of materialsincluding those that are brittle and so need to be carefully handled andprotected from shattering.

The casing 2 is formed from the front face 3 surrounded by the bezel 19,a side frame 20 and a back cover 21. The interface between the sideframe 20 and the bezel 19 and the side frame 20 and the rear cover 21are shielded by rails 22, 23 in this embodiment. The rails 22, 23 hideraw edges from view and exposure to ensure that the device 1 is bothlong lasting and elegant. The construction of the casing 2 enables thecasing 2 to be opened with ease to update the engine 24 inside whendesired. The casing 2 is also designed to allow the device toaccommodate different sized and shaped engines 24, which may benecessary through its life.

Other elements of the design will be discussed in greater detail withreference to the later drawings. By way of introduction, the device willbe briefly discussed with reference to its functional elements.

The communication device 1, includes the key array 6, a display 25, anantenna 26, an ear piece speaker 18, a polyphonic speaker 27, and amicrophone 28. The communication device 1 is adapted for communicationvia a wireless telecommunication network, e.g. a wireless network.However, the communication device could also have been designed for acordless network. FIG. 3 shows schematically and functionally elementsof the communication device 1. The microphone 28 records the user'sspeech, and the analogue signals formed thereby are A/D converted by anA/D converter before the speech is encoded in an audio part 29. Theencoded speech signal is transferred to processor 30. The processor 30may support software in the phone. The processor 30 also forms theinterface to peripheral units of the apparatus. These may include aRandom Access Memory (RAM) 31 and a Flash Read Only Memory (ROM) 32, aSIM card 33, the display 25, and the key array 6, and perhaps a browserapplication 34, and a location module 35.

The browser application 34 can be used to request and receiveinformation from the Internet. The location module 35 enables theterminal 1 to determine its current position.

The processor 30 communicates with a transceiver 36, e.g. a circuit,which is adapted to send and receive messages in a telecommunicationnetwork. The telecommunications network may be a GSM or W-CDMA network,but the invention may also be applied in connection with any othernetwork, including but not limited to other kinds of wireless networksand various forms of cordless phone systems or in dual band phonesaccessing sets of these systems or networks. The audio part 29speech-decodes the signal, which is transferred from the processor 30 tothe earpiece 18 via a D/A converter.

The display 25 may form a permanent part of the casing or, to increasethe potential for upgrading the engine throughout the life of the casingit may be a module that can be replaced to, for example, account for theinevitable improvements in graphics that may occur.

As discussed above, the front face 3 is optically permeable and acts asa light guide. The seamless light guide, passing light over the displayregion 4 as well as providing light to illuminate the key legends 15reduces the number of lighting elements required to illuminate thedevice and provides a seamless transition from one area of the front ofthe device to another. By using this technique for delivering light andalso allowing the light guide 14 to form the front surface of the device1 as in the embodiment disclosed, the device is visually striking, therebeing no visible transition from the display region 4 to the inputregion 5 where the key array 6 is located.

The embodiment illustrated in FIG. 1 has a light permeable front face 3that can be formed from sapphire or a similar precious stone. As soon asa mineral such as sapphire is used in place of other more flexible lightpermeable materials such as plastics, additional problems are introducedassociated with the character of the material. In designing a durabledevice having, for example, a brittle material for a front piece 3 thereare many difficulties. In one manifestation of the embodimentillustrated in FIGS. 1, 2 and 4 to 6, the light guide 14 is an opticallyseamless composite layer. As can be seen most clearly in FIG. 4, aplastics layer 37 that may be formed from Perspex or other transparentand/or translucent materials runs the entire length of the front face 3.There is a cut-out 38 for accommodating the ear piece speaker 18 that isoptimised for use close to the ear. There is another cut-outaccommodating a light pipe diffuser 39. This is located under the pillow16 and extends across the width of the device 1. By placing the lightpipe 39 under the pillow 16, a bright area on the front face is avoidedand the light visible in the light guide will be diffused. LEDs 40, 41are located at each side of the device at each end of the pipe 39. Lightfrom the LEDs 40, 41 is channelled through the pipe 39 and diffused. Thelight pipe 39 in this embodiment is coated with reflective material sothat light is channelled through the surface 42 that runs along the topof the LCD display 25. Embodiments without the coating provide some ofthe advantages. The diffused light is accordingly channelled into andalong the major axis of the light guide 14 to provide substantiallyuniform lighting for the LCD 25.

In this way light is pumped into the light guide 14 along the major axisfrom above the LCD 25. The light from the light pipe 39 illuminates thedisplay region 4 and provides lighting for the input region 5. Asillustrated in FIG. 15, additional LEDs 43 or other lighting elementsare positioned along the edges of the Perspex layer or sheet 37 in theinput region 5 to further illuminate the legends 15 for the keys of thearray 6. The surface of extending portions 78 of the Perspex layer orsheet 37 is shaped to channel light from adjacent top firing LEDs 43 orthe like towards the upper surface of the main portion of the layer orsheet 37. This assists in providing substantially uniform lighting forthe input region. The additional LEDs 43 or the like are shielded fromview by the bezel 19 to avoid light spots being visible and encouraginga uniform diffuse light across the light guide.

The LCD 25 itself is bonded to the rear surface of the Perspex sheet 37with an energy absorbing adhesive sheet 45. Using this technique andensuring that there are no air gaps between the front of the LCD 25 andthe Perspex sheet 37, provides a robust solution for mounting the LCD25. The surface of the LCD 25 that is delicate and generally needs aprotective layer distanced from it is protected by the Perspex layer 37adhered to one of its faces. The drivers 44 for the LCD 25 can be seenin FIG. 5.

In the embodiment illustrated the Perspex layer 37 includes apertures 48for locating individual keys and allowing the key shafts 49 to travel tomake contact with a printed circuit board 50 located within the casing 2to register user input. An independently inventive key layout, suitablefor use with the general concept discussed, will be described in greaterdetail below. As the key layout is likely to be one of the most enduringelements of the design, it has been designed with future requirementsfor the casing in mind. The skilled man will be aware that modificationsto the key arrangement can be made while still providing the flexibilityto accommodate future engine requirements. For example, a joystick, orsimilar rotational device or multi-directional key could be utilised forinput as could other input mechanisms traditionally used on laptopcomputers.

As can be seen most clearly from FIG. 4, the second layer of thecomposite light guide 51 is made in a number of sections 52-58. This isto allow for the choice of brittle materials to be used for the secondlayer 51. Sapphire has properties including its scratch resistance andoptical clarity that make it suitable for use in this context althoughthe material of this element is selectable a ceramic material could beutilised in this arrangement. Other suitable materials are glass andother minerals and precious and semi precious stones. When a transparentmaterial such as sapphire is used, however, the light guide provides anexternal surface to the device. Arrangements for the second layersimilar to those disclosed in concept in the illustrated embodiment arenot necessary when the materials are not brittle. Alternativearrangements will, however, be apparent to the skilled man foraccommodating brittle materials in this context.

As mentioned above sapphire is brittle. When considering how tointroduce such a material into a casing 2 that is to be long lasting anddurable, problems arise. This is particularly the case when the device 1will inevitably be subjected to knocks and is likely to be dropped manytimes in its long existence. All brittle parts are bonded to a carrierformed from e.g. plastic or titanium in order to better absorb shock. Inthe embodiment described, the sapphire is formed in individual sections52-58 for ease of manufacture. Each of the pieces is adhered to thePerspex layer 37 using a UV curing adhesive based on hybrid acrylictechnology. In order to increase the durability of the composite lightguide 14 and strengthen it against damage, the sections 52-58 areadhered to a more flexible Perspex layer 37 leaving gaps 59 extendingacross the entire width. These gaps 59 act as hinges to allow thecomposite layer 14 to be relatively flexible along its major axis. Inthe embodiment illustrated, the layout of the key array 6 has beendesigned with this in mind. The alpha numeric keys 7 are arranged ingroups of three extending across the whole width of the second layer ofthe composite 51. The function keys or soft key 8, 9 are also arrangedin two groups of three. The soft keys 8, 9 and the top scroll key 12 afollows the line of the alpha numeric keys 7. The call handling keys 10,11 and the bottom scroll key 12 b, which is displaced from the line ofthe others, defines the lower edge of one of the elements 57 and theupper edge of another of the elements 56. This makes the second row ofkeys 10, 11, 12 b distinctive whilst still avoiding problems inmanufacture of the elements 52-58. The specific key array 6 illustratedhas other properties and advantages that will be discussed later.

Although the embodiment described is designed with a brittle materialsuch as sapphire in mind, the resultant arrangement could be formed fromany number of other materials including plastics that provide therequired optical characteristics. Similarly different key arrangementscould be used without departing from individually inventive conceptsthat are disclosed.

When using a brittle material for a front face light guide 14 problemsare also encountered when connecting the front face 3 to the rest of thecasing elements. In the illustrated embodiment the edges of the brittleelements 52-58 are protected by the bezel 19 that sits around the wholeof the face. The bezel 19, in this embodiment, is formed from a bezelsupport 60 overlaid with a 0.5 mm thick metal sheet, the bezel cover 61.The metal sheet 61 is bonded to the bezel support 60, that may be formedfrom plastic, with an adhesive such as a two part epoxy adhesive or atwo part acrylic adhesive. As the metal sheet 61 is relatively thin thiskeeps the weight of the casing 2 down and also allows relativelyprecious metals such as titanium or gold to be used at relatively lowercost. The bezel 19 could, however, be a single part and/or be formedfrom a single material for example titanium.

The transparent face 3 in this particular embodiment is securely held inplace by a robust mechanism. The Perspex layer 37 to which the elements52-58 are bonded extends beyond the area covered by the elements toprovide a lip or edge 62 around the whole of the composite light guide14. This edge 62 is used to secure the front face 3 in position as it istucked under the bezel 19 that defines the perimeter of the front faceand squeezed between the bezel 19 and the side frame 20.

As can be seen in FIG. 1, the bezel 19 is punctuated with front faceprotectors 63 whose function will be described in more detail later.These front face protectors 63, in this particular embodiment play arole in holding the casing elements together.

The front face protectors 63 have a tip part 64 that extends over thebezel 19 and a shaft 65 that passes through the bezel 19 and into theplastic side frame 20. The shaft 65 may be tightened onto the frame 20using a nut 95. In this case the nut stops the front face protectorsfrom falling out of the device. In one embodiment the shafts 65 arescrewed into the tips 64 at one end and into the side frame element 20at the other although other manners of connection could be employed. Theshaft 65 and tip 64 could also be one piece rather than two. The bezel19 and the Perspex layer 37 of the transparent face 2 are captured bythe front face protector 63 and side frame element 20 as can be seen inFIG. 9 b. The front face protectors 63 accordingly grip the transparentface 3 securely between the side frame 20 and the bezel 19. The frontface protectors 63 are only located next to the key array 6. In order tosecure the transparent face 3 around its perimeter additional screws 66are added to draw the bezel 19 towards the side frame 20 and squeeze thetransparent face 3 in place. In one embodiment, the screws 66 threadthrough the side frame 20 and tap into the bezel support 60. Once thebezel support 60 is secured to the side frame 20 the outer shell 61 ofthe bezel 19 can be adhered to the support 60 to hide the tapped screwends 66. Alternatively the bezel 19 is stuck to the support first (asub-assembly) and this sub-assembly is then screwed to the frame.

As can be seen in the figures, although the more flexible transparentsubstrate 37 is overlaid by the bezel 19 secured in position by thefront face protectors 63 and other connectors, the sapphire ismaintained spaced from the bezel 19 so that it is protected fromchipping or other damage as a result of contact. The edges of thesapphire elements do not protrude above the edge of the bezel 19 toprovide further protection for the more vulnerable edges. In thearrangement described, the transparent face 3 is gripped in positionbetween the bezel 19 and the side frame 20. The more flexible substrate37 could, however receive screws or other fasteners to located itrelative to the other frame members without damaging the more brittlesapphire layer. The choice of material for the bezel is one open toselection. Precious metals including gold, platinum, silver, steelamongst others would be suitable. The same applies to the material ofthe front face protectors. Both these elements and others that theskilled man will realise are suitable could be encrusted with preciousor semi precious stones such as sapphires, rubies, emeralds and diamondsamongst others. Other crystals or minerals or other materials andveneers could also be utilised.

To reduce the ingress of dirt or fluids a sealant 69 is located betweenthe bezel 19 and the transparent face 3. One way in which this can beintroduced is to paint a seal on the underside of the bezel 19 whichwhen dry is compressed between the transparent light guide 14 and thebezel 19 when the bezel 19 and the side frame 20 are pulled together.

As can be seen in FIG. 6 or 9, a first rail 22 is located in theinterface between the side frame element 20 and the front face 3. Therail 22 hides the discontinuity between the parts from sight andprotects vulnerable edges to enhance the durability of the device 1. Therail 22 may be a stamped metal piece ‘T’ shaped in section extendingaround the perimeter of the side frame 20. The stem of the ‘T’ 68 istrapped between the side frame member 20 and the bezel 19 as these twopieces are drawn together on assembly. The stem of the T has apertures70 that sit over corresponding projections 71 on the side frame 20member to prevent it from being withdrawn from between the two partswhen in position. The top of the T acts as a carrier plate to which anadditional extruded piece 72 is soldered or otherwise adhered to providea seamless finish. The stem could instead be formed from a plasticsmaterial.

The side frame member 20 in this particular embodiment is a plasticsupport 73 with an exterior cover 74. The cover 74 may again be a metalsheet formed, for example, from a precious metal or perhaps a woodveneer or another layer such as leather or other skin. The bonding agentmost suitable for adhering the layer to the plastic frame member 73 willdiffer depending upon the materials that need to be adhered. For metalto plastic a suitable adhesive is a 2 part epoxy resin or 2 part acrylicadhesive. For metal to metal the adhesive would be a reactivepolyurethane film or a two part epoxy resin. Similarly the back cover 21in this embodiment may have a plastic frame and be covered with forexample a leather, wood or perhaps metal veneer. With the flexibleveneer materials such as leather, it is preferable for the material tobe taut on the frame. This is achieved during the veneering processusing conventional techniques.

The transparent face 3 provides a seamless transition between thedisplay 4 and the input regions 5. In the display region 4, the LCD 25is located behind the transparent face 3 and in the input region 5 thekey mechanism 75 lies behind it. In one embodiment described, the keymechanism 75 can be seen through the front face 3. However, in otherembodiments the inner surface 76 of the Perspex substrate 37 may becoated with an opaque material to prevent the inside of the device beingseen. Alternative methods of obscuring the inner workings of the devicefrom view such as introducing additional opaque layers or obscuring theview in other ways will be apparent to the skilled man.

For embodiments where, for example, the key operating mechanism 75 canbe viewed through the front face 3, it may be desirable to obscure thePCB 50 from view.

The constructed casing 2 provides a housing for the printed circuitboard 50 holding the engine components 24, and a battery 79. When thedevice 1 is a radio telephone, a SIM card holder 80 is provided toaccommodate a SIM card 81. For operation under some radio protocols thiswill clearly not be necessary.

Returning briefly to the front of the device, located above the displayregion 4 is the pillow 16 so named because it designed for the user torest his or her ear against when making a telephone call. The pillow 16overlays the ear piece 18 of the device. As described previously thereis a cut-out in the Perspex substrate 37 of the light guide 14 toaccommodate the ear piece. 18, the pillow 16, in the illustratedembodiment is adhered to the Perspex substrate 37 covering the ear piece18. The pillow 16 provides suitable apertures 17 to channel sound to theuser. The characteristics of pillow 16 both in terms of the material andsurface decoration may be selectable by a commissioning party.

The Perspex and sapphire light guide 14 is relatively cold to the touch,the material of the pillow 16 can be chosen to be a material that isinherently warmer to the touch and less prone to marking than atransparent shiny surface. Materials that are thought to be particularlysuitable are ceramics or wood and leather veneers. The shape of thepillow 16 obscures part of the LCD 25, providing opposing triangularsections 82, 83 that are used to indicate battery capacity and signalstrength respectively.

To complete the structure, the casing 2 has a rear cover 21 and internalcompartments 84, 85 suitable for retaining the engine 24 the battery 79and in this embodiment a SIM card 81. The device illustrated, in commonwith many other radio telephones, advantageously allows access to thebattery compartment 85 as the battery 79 may periodically needreplacement. In order for the engine 24 to be protected during thisactivity, the battery 79 is retained in a compartment providingconnectors to the engine 24. Along side the battery compartment 85 inthis embodiment is the SIM card holder 80. Under protocols where a SIMcard 81 is used to hold subscription information, the user may wish toremove the SIM card 81. For this reason it is convenient for the backcover 21 to be removable to expose both the battery 79 and the SIM card81. The battery compartment 85 and SIM card holder 80 are provided by aninternal casing element 87 that is secured to the side frame 20. Thismay be formed from plastic or one of many other suitable materials. Inone embodiment the compartments are formed from stamped metal sheetwhich may be stainless steel.

The battery contacts 90 protrude into the battery cavity 85 to provide asimple way of connecting the battery 79 to the engine 24. The batteryconnection will typically have a power connector 91, a ground 92 and twosignal connectors 93, 94.

In the embodiment illustrated, the power 91 a,b,c and ground 92 a,b,cconnectors are divided into three. This reduces the resistance betweenthe battery 79 and the engine 24 as the leads are in parallel, it alsoreduces the chance of power being lost to the engine 24 as a result of aharmonic resonance frequency of the connector being reached as at alltimes there is likely to be at least part of each three part connectorcompleting the circuit between the engine 24 and the battery 79.

The casing 2 is completed by assembling the back cover 21 to the sideframe 20. In the illustrated embodiment, the back cover 21 is formedfrom three pieces 96, 97, 98. A first piece 96 overlays the antennalocation. In this embodiment it provides an aperture 99 in which thepolyphonic speaker 27 is located to provide for polyphonic sound. Thisadditional speaker 27 has not been optimised for use in close proximityto the ear as has the speaker 18 located beneath the pillow 16. Thisallows it to be more effective as a handsfree speaker and enables agreater range of ring tones to be utilised. As the first piece 96 alsocovers the antenna its dielectric constant is relevant.

In a device of this type where the casing 2 is to survive generations ofengines 24, the materials from which is formed are important. Theyshould be hard wearing and durable, retaining their attributes for yearslonger than is currently required. For this reason ceramics have beenconsidered as an option for the back cover 21 for some embodiments ofthe invention. Other materials already discussed such as metals orprecious metals or veneers would also be possible. With ceramics,however, despite having many desirable characteristics, for locationsnear an antenna relevant for devices containing such an element, thedielectric constant of the material interferes with the desiredtransmission pattern.

To provide many of their desirable characteristics without thedielectric constant becoming too high, the rear cover piece 96 can beformed from a material with a lower dielectric constant with a suitabledepth of layer deposited on it. This technique and suggested materialscould be used for other elements of the casing.

The rear casing element 96 covering the antenna is again screwed to theside frame element 20 and in the process captures the second rail 23similar in construction to the first rail 22 between the side frame 20and the back cover 21. Again the rail 23 is provided with apertures 70that are positioned over corresponding projections 71 on the side frame20 to more securely hold the rail 23 in position when the back cover 21is attached.

A second rear casing element 97 covers the battery compartment 85 andthe SIM card holder 80. This element is releasably secured to the othercasing elements using screws 99 to allow relatively easy access to theSIM card 81 and battery 79. In a preferred embodiment a quarter turn ofa screw 100 releases the cover element 97 to allow it to be removed. Thesame action can disconnect the battery 79 to allow the SIM card 81 to beremoved.

The second rear casing element 97 is attached to the side frame 20 in asimilar manner to that described in relation to the first rear casingelement.

The third element of the rear casing 98 covers the handsfree speaker 27.This may be only relatively thin and formed from a precious materialsuch as gold. It will be provided with a suitable aperture 102 tochannel sound from the polyphonic speaker 27 that may be used in handsfree mode and for providing an audible ring tone.

In the embodiment described the front 3 and rear casing elements 96, 97,98 are secured to the side frame 20. A silicon sealant 69 or similar maybe extruded around the inside of the back cover 21 to prevent unwantedingress of dirt and fluid.

The skilled man will realise that the number of parts and the manner inwhich they are connected can be changed without departing from theseveral inventive concepts described. For example, in other embodimentsthe casing may be held together using other techniques and in otherways.

As well as obscuring exposed edges, the rails 22, 23 provide additionalelements for customisation as they can be formed from a variety ofdifferent materials, in particular different types of precious metal forexample gold or platinum as discussed previously in relation to thebezel. The material for the entire ‘T’shaped piece or the extrudedelement could be a precious metal. They also act to protect vulnerableedges of veneered frames from exposure to potentially damaging forces.In doing this unsightly edges are obscured from view. This providesquality and durability in keeping with the overall concept of aretainable casing for a communications device. Regardless of thematerial of the veneer, this is a convenient arrangement for securingall the elements in place for a durable finish.

In an alternative embodiment illustrated in FIG. 4 b, instead ofproviding rails 22, 23 to protect exposed edges, the adjacent edgesthemselves are turned inward 105, 106 and held in close proximity. Thisarrangement also provides the advantage of protection and keepsunsightly discontinuities from view.

A casing with an optically permeable front face provides newopportunities. In a particular embodiment, described with reference toFIGS. 12 and 14 legends 15 associated with the keys of the key array 6are located on both the front 37 a and rear 37 b surfaces of the Perspexlayer 37. With communications devices becoming ever more sophisticated,it is common for each key provided to have a number of differentfunctions. It is useful to be able to label visually the differentpossible functions associated with a key. For the alpha numeric keys 7in particular, each key is associated with a single digit and a group ofletters or symbols. Ideally these should be displayed clearly.

Historically the keys have held the associated legends. As devices havebecome smaller this has, however, becomes more difficult, it being anespecial problem to distinguish between the different legends forrespective modes of operation as the letters and numbers are so small.In the illustrated embodiment, the legends 15 for associated keys arelocated on respective surfaces of the light guide 14 which, as thedevice is tilted, move together or apart depending upon the angle fromwhich they are viewed. This provides a visual distinction between thelegends 15 on the different surfaces which can be used to distinguishbetween the modes of operation. As the front face is opticallypermeable, the legends appear to float in or above the device. Byspacing the legends along an axis perpendicular to the third dimension,the thickness of the front face, the front face is given someprominence, thus an additional dimension has been added to the normallyopaque front face.

In the embodiment illustrated the legends 15 are located on theoutermost and innermost surfaces of the Perspex layer 37 a, 37 b. Thelegends 15 appear to be floating in the light permeable layer. Themanner in which the legend 15 is located on the layer is a matter ofchoice for the skilled man. One method is to print the legend on to thesurface using an etched plate filled with ink. Another way may be byusing PVD (Physical Vapour Deposition) techniques to deposit the‘printing’ directly onto the Perspex layer. Other techniques for fixinglegends could be used including attaching labels.

In the embodiment discussed the legends 15 a 15 b are located onopposing surfaces of the Perspex layer 37 a 37 b. This enables a singleelement, the Perspex layer 37, to be printed instead of each of thesapphire or other pieces 52-58. Problems encountered with ink wearingoff when printing techniques are used are also avoided by protecting thesurfaces containing the printing with the second layer. In otherembodiments and to increase the depth of spacing of the legends andhence the separations possible when viewed at different angles it may bedesirable to place the legends on the innermost 37 a and outermostsurfaces 51 a of the composite. In order to fix the legend 15 printed onthe outer surface 51 a where it may encounter wear, a coating or otherprotective layer may be provided over the surface. This may not benecessary if PVD techniques are used to produce the legend 15 as suchtechniques produce a bond between the deposited layer and the substratethat is more hard wearing. In still other embodiments the legend 15could be provided on the underside 51 b of the sapphire elements and onthe innermost layer of the Perspex substrate 37 b. Again by avoiding theexternal surfaces of the transparent layer the problem of wear of thelegends 15 is largely avoided. The outermost legend is protected by thetop layer 51 of the composite light guide 14 and the innermost legend 15is not accessible.

In sandwiching the legends between two optically permeable layers 37, 51which of the two sandwiching layers carries the legend is largelyimmaterial. The properties of the respective materials, if indeed theyare different, and other factors can be taken into account in decidingwhich layer 37 b, 51 b actually carries the legend. With a compositeoptically permeable substrate, the more layers that are provided, themore visually distinguishable legends can be accommodated. For examplewith two composite layers there are three available planes for legends,with three layers, four planes and so on. If all the legends were placedadjacent a single key, the visual distinction may cause difficulty withlarge numbers of layers being used to distinguish functionalities. Otherembodiments could use the different planes for legends at differentlocations on the device so that one set of keys has a legend in a firstplane, a second set of keys in a second plane and so on.

To accentuate the illusion of the legends floating, or to increase thedistinction between the two layers, the thickness of the opticallypermeable layer between the respective layers carrying the legends canbe increased. In the same way these features can be reduced bydecreasing the thickness between the planes carrying the legends.

The ink or paint can be chosen by the skilled man to provide a number ofeffects. The ink may, for example, be required to pearlesce orfluoresce, or be black, white, or one or more of a wide range ofcolours. As the legend is located on a light guide, fluorescent andpearlescent materials enhance the visibility of the legends. The typescript, colour or other character of the legend or element carrying thelegend may be selected by a commissioning party.

Instead of techniques that add ink or other visible materials to thesurface merely etching the layers may be sufficient to make the legendsvisible if the illumination is adequate.

Embodiments illustrating the location of legends associated with keys ina light permeable face has been described with reference to theillustrated embodiments in the context of other independently inventivefeatures claimed in copending applications. The skilled man will realisethat many alterations to the specific features disclosed can be madewithout departing from the scope of the invention.

The skilled man will be aware that the character described above inrelation to specific elements of the device can be mixed and matched tosuit many distinct design options.

The input region of the device will now be described in more detail,primarily with regard to FIGS. 9 and 15 to 21

The input region 5 comprises a key array 6, as described above. In thisembodiment, the key array is made up of a plurality of individual keys7-13.

Each of these individual keys comprises a key tip 64 and shaft 49extending from substantially the centre of the key tip 64, together withan upper bearing 103, O ring 107, circlet 108, spring plate 110 andlower bearing 109 positioned respectively along the shaft 49 a from thekey tip 64. The spring plate 110 is supported by a spring plate support114 provided on the PCB 118. The spring plate comprises a main body, anda tongue 111 formed from a single piece of sheet metal. The tongue hasbeen formed by stamping an inner portion of the sheet, so that two sidesand an end of the tongue are free from the remaining main body of thesheet. The spring plate also has a portion or portions stamped out toprovide an aperture for the key shaft 49 and spring plate support 114.One end 113 of the spring plate comprises contacts for contactingrespective contact regions on the PCB. As will be appreciated by aperson skilled in the art, a single contact could be used for thispurpose, but the provision of two contacts provides greater reliability.The spring plate support 114 comprises three members upstanding from thePCB 118. These members may form part of a unitary structure, or may beseparate elements. The first member comprises a recess 115 dimensionedto receive one end 112 of the spring plate 110 and hold that end 112 inposition. The second member of the support 114 comprises a lip 116extending towards the first member. This lip 116 is provided to restrictthe upward movement of the other end 113 of the spring plate 110. Thethird member of the support 114 comprises a recess 117 for receiving theend of the tongue. This third member is positioned relative to thesecond member, such that the tongue of the spring plate 110 has to beflexed in order for the end of the tongue to correspond with its recess117. Optionally, the spring plate support may comprise a fourth membercomprising a lip extending towards the second member. In this case, thePCB contact regions are extended to the surface of this lip, so as tobring them closer to the spring plate contacts. Alternatively thecontact region bearing lip may be formed as part of the second memberitself, or eliminated altogether.

As mentioned above, in the present embodiment, the individual keys aregrouped in threes, their tips extending across the whole width of thesecond layer of the composite 51. This facilitates manufacture of thebrittle elements 52 to 58. The tips of the alphanumeric keys 7, softkeys 8, 9 and top scroll key 12 a are in alignment with those of theother keys in their group. In the remaining group of keys, however, thetip of the bottom scroll key 12 b is displaced from the line of the tipsof the other two keys in its group, namely the call handling keys 10,11. In any event, in each group the edges of adjacent key tipscomplement each other, and are closely spaced. This eliminates the needfor the composite 51, or other filler material, to extend between thekey tips. It also has the advantage of simplifying the overallappearance of the input region of the device to the user. Furtherproperties and advantages of the specific key array 6 will be discussedbelow.

As can be seen in particular from FIGS. 17 and 18, the spring plates 110and supports 114 of adjacent alphanumeric keys 7 are positionedperpendicular to each other. This provides a geometrically simplesolution to the problem that the spring plates cannot be positioned inalignment with the keys themselves. One cause of this problem in theembodiment illustrated is that the spring plate of each outer key islonger than the average length of its corresponding key tip, and thisextra length cannot be accommodated elsewhere. This is primarily becausethe spring plate of each central key is only minimally smaller than theaverage length of the corresponding key tip, and the keys are closelyabutted (there is only a gap of about 0.245 between the keys) so thatthere is insufficient space to allow for the extra length. Furthermore,whilst the key shaft 49 of each key is substantially central to the keytip 64, the key shaft aperture of the spring plate 110 is off-centre.This exacerbates the problem for the outer keys, and even results in thespring plate of each centre key not being able to be accommodated in thespace under its corresponding key tip.

The keys may be constructed, and the input region of the deviceassembled as follows. Upper bearings are inserted into the apertures 48of the Perspex layer of the device. Ruby bearings are preferablyselected for this purpose, for three main reasons. Firstly, ruby is veryhard wearing, and will thus be able to handle multiple operations of thekeys over a substantial period of time. Secondly, the upper bearings ofthis device are larger in diameter than the corresponding widths of thekey tips, which means that they will be visible in situations in whichthe front face of the device is transparent (e.g. second layer 51 may besapphire). Hence, advantage may be taken of the fact that a ruby is anattractive jewel, which the user will be pleased to see. Thirdly, theuse of a hard material such as ruby will provide greater accuracy of fitof the key in the device, as opposed to using a resilient material, suchas PFTE.

Lower bearings 109 are provided in a titanium plate which is fixed tothe rear of the PCB 118. The inner and outer diameter of the lowerbearings 109 are smaller than the upper bearings 103, but their centresare aligned. They are also preferably made of different material—thematerial of the lower bearings having shock absorbing qualities such asPFTE.

The key shafts 49 are machined, to have a first portion 49 a ofappropriate thickness to pass through the inner diameter of the upperbearings 103 and a second reduced diameter portion 49 to pass throughthe inner diameter of the lower bearings 109. Shaft 49 and circlet 108may be machined from a single piece of metal, or the circlet 108 may besubsequently attached to the shaft 49. They are preferably formed ofstainless steel. Further, an O ring 107 is provided adjacent the circlet108, on the thicker diameter portion 49 a of the shaft 49, to provide awater seal. Both the circlet 108 and the O ring have an outer diametersmaller than that of the upper bearing, so that they are not visible tothe user when in situ. However, the circlet has an outer diametersufficiently larger than the inner diameter of the upper bearing, so asto prevent the key from falling out of the device.

The key tips are crafted into the desired shape from a desired material,which may be a metal such as gold, platinum, silver, or stainless steel.They may also bear precious stones. For example a key tip or tips may bediamond encrusted, or have a precious stone set in it. Once a key shafthas been passed through an upper bearing, a key tip is joined to it.This may be achieved using conventional braising techniques.

The spring plate supports 114 are provided on the PCB 118. Each springplate support 114 is preferably of unitary structure, manufactured fromlightweight metal such as aluminium. The supports may then be solderedonto the PCB using conventional techniques. The spring plate supports114 are positioned to hold the spring plates 110 so that the centres oftheir shaft apertures align with those of the lower bearings 109.Contact regions for the spring plate contacts are provided on the PCB(or the lip of the second or fourth member of the support as describedabove).

The spring plates 110 themselves are provided by stamping sheet metal,such as beryllium cooper with gold flash or the like. The plates 110 areaffixed to the supports 114 by positioning one end 113 of the springplate under the lip 116 of the second member of the support 114, fittingthe other end 112 of the spring plate in the recess 115 of the firstmember of the support 114, flexing the tongue so that its endcorresponds to the recess 117 of the third member of the support 114,and positioning the end of the tongue in that recess. When in position,the free end 113 of the spring plate 110 is naturally biased upwardstoward the restraining lip 116.

The dimensions of various components of the keys and their relativepositions are important in smooth key operation. The distance betweenthe upper and lower bearings has been maximised by placing them eitherside of the spring plate switching mechanism and passing the shaftthrough the spring plate. In such a position, the bearings hold the keystraight when it is operated, thereby avoiding contact with neighbouringkey tips or the need to place keys further apart to prevent suchcontact. This, in turn, results in good switching functionality andfeel.

Also, the dimensions of the keys are such that the lower surface of eachkey tip 64 contacts the surface of the Perspex layer 37 before excesspressure can be applied to the spring plate 110. In the presentembodiment, the circlet 108 is positioned along the shaft such that itgently rests on the spring plate when the keys are in their normalnon-depressed state. Also, the thicker portion of the shaft is of anappropriate length that, when in the normal state, there is a gapbetween the lower surface of the key tips and the surface of the Perspexlayer 37 which is the same as, or only slightly greater than thedistance the circlet 108 has to travel to cause the spring platecontacts to contact the contact regions. This overcomes a potentialproblem of pressure being applied to the spring plate if the switchitself provides the end stop for the motion.

The dimensions of the keys are also important for the externalappearance of the device. Preferably, the key tips are of a thicknessthat they protrude from the surface of the second layer 51 of thecomposite, at least when the keys are in the aforementioned normalstate. When the composite is substantially transparent, this will givethe impression of floating keys, and add to the three dimensional effectmentioned earlier concerning the key legends 15. Furthermore, the keytips should be sufficiently deep to be partially sunk into the secondlayer of the composite, and preferably have at least two opposingsubstantially flat sides which correspond with sides of the second layerto prevent lateral rotation of the keys. A gap of the order of 0.1 mm isachieved in the present device between the keys and second layer of thecomposite: a gap insignificant to the human eye and suitable forassisting in the prevention of lateral rotation of the keys. Lateralrotation is further hindered in the present embodiment, by virtue of theprovision of mirrored slanting of the sides of adjacent keys.

In order to ensure the correct relative spacing of elements of the key,the Perspex layer 37, PCB 118, and titanium plate 77 are clampedtogether. In this embodiment, the clamping is provided by the front faceprotectors 63, and by the provision of additional tapped bosses inprojections 68 of the Perspex plate and associated fixing means.Consequently, once the keys have been positioned, the Perspex layer, PCBand titanium plate can be clamped together using the bosses and fixingmeans, thereby holding the keys in place and forming a manageablemodule. This module may then be readily installed in the device usingthe front face protectors as described above with reference to FIG. 9B.

Operation of the keys of the device will now be described. As the userapplies pressure to a key tip, the shaft moves downwards, travellingthrough the bearings and shaft aperture of the spring plate. Thisresults in the circlet applying pressure to the part of the main body ofthe spring plate which defines the shaft aperture. Continued pressure onthe key tip will then cause the circlet to apply an increasing force tothis part of the spring plate, causing the main body to deform aroundthe circlet. Eventually, this deformation will cause the tongue toovercentre, resulting in the free end 113 of the spring plate 110flicking from its naturally biased position (upwards towards therestraining lip 116) to a second position, in which the spring platecontacts contact the contact regions on the PCB. An electrical signal isconsequently sent to the processor indicative of actuation of that key.This arrangement gives a distinct click providing a clear qualityindication to the user that the key has been actuated. As the userremoves pressure from the key tip, the circlet, in turn, removespressure from the spring plate 110. The tongue promptly returns to itsnormal position, and the free end of the spring plate flicks up to itsnaturally biased position, breaking the contact.

FIG. 20 a is a graph illustrating the force against distance profile fora key such as that illustrated in FIGS. 17 and 18. This profile improvesthe tactility of the key over, for example, a typical keydomearrangement, which had a fairly flat profile as can be seen in FIG. 20b. When using a conventional key dome type arrangement, the user has toapply a constant force until the point where the key actuates. As aresult, he does not get a tactile indication that he is nearing theposition when actuation is likely to occur. In contrast, when using thedevice illustrated in FIGS. 17 and 18, the user can realise the factthat he is nearing the position when actuation is likely to occur as heis having to increase the force applied for a given travel of the key.Furthermore, the user is informed when actuation takes place, and againwhen deactuation takes place, by respective clicking sounds provided bythe key.

The central V shaped key tips of the embodiment illustrated in FIG. 1enable the user to determine the central vertical axis of the deviceboth by sight and by touch. This is made even easier by the pillow 16being provided with an apex. Consequently the user can quickly locate adesired central key. The apexes of each central key tip also identifythe mid point along the length of the key tip, the point from which thekey shaft 49 extends. Hence, they facilitate more accurate depression ofthe key. This, in turn, may assist in the prevention of contact withneighbouring key tips or the need to place keys further apart to preventsuch contact.

Likewise, in this embodiment, the combination of adjacent outer key tipsand front face protectors forming a V shape enable the user to determinethe position of the vertical axes to one side of which the outer keyslie. Consequently, the user can quickly locate a desired outer key. Thekey location process is facilitated in this embodiment as the outer keytips extend to the interface between the second layer of the composite51 and the bezel 19.

The front face of the device illustrated in FIG. 1 is protected by thepillow and front face protectors, 63. The front face 3 is slightlyconvex, with the highest points lying along its central longitudinalaxis. Hence, ordinarily, if placed face down, the device would rest onthis axis, resulting in scratches to its surface. Clearly, this is notacceptable, particularly when the second layer of composite is sapphireor the like. The device illustrated in FIG. 1 has been designed to avoidthis problem. The pillow 16 and face protector 63 a prevent the deviceresting on the second layer of composite. Also, as mentioned above, inthe preferred embodiment the key tips protrude slightly from thesurface. Hence, the central key tips too may protect the second layer ofcomposite from damage. However, preferably the pillow 16 and chin frontface protector 63 a are raised sufficiently above the front surface,that the device does not rest on the central key tips either, so as toprotect them from damage too.

The device is also designed so that the front face is protected if theedge of the face is knocked. As can be seen from the plan view of thedevice, depicted in FIG. 21, the bezel front face protectors 63 bprotrude beyond the surface of the second layer of composite along theinterface with the bezel, thereby protecting the second layer ofcomposite from damage in that region. They also reduce the likelihood ofdamage to the bezel due to knocks. Moreover, they protrude further thanthe adjacent key tips, hence protecting those key tips from damage too.

One further benefit of the front face protectors 63, particularly thebezel is that they are dimensioned so as to prevent the keys from beingaccidentally actuated if, for example, the device was placed face down.That is, the top surface of the front face protector tips should eitherbe at the same level or higher than the top surface of a key tip (e.g.as in the relationship between the protectors 63 b and the adjacentouter key tips) or, if they are at a lower level than the top surface ofa key tip, the distance between the top surface of the protector and keytips must be smaller than the distance the key needs to travel in orderfor the spring plate contacts to contact the PCB contact region foractuation the key.

In order to commission a casing for a portable communications devicethere will be a list of designated casing elements the characteristicsof which are selectable by a commissioning party. This list of possibleparts for personalisation may be provided in amongst other ways on acomputer, on a web site or as a paper list in a suitable store. Theparty commissioning the device can then select the characteristics ofthe designated elements from a set of possible options provided. Inalternative embodiments the scope for originality in the characteristicsof individual ones of the designated elements may be greater and thecommissioner may be given a practically free hand in determining thematerial, and other additions such as surface decoration by etching orengraving and, amongst other things, encrustation.

The entire process could be computerised so that the selected charactersof the device are readily conveyed to a manufacturing location orlocation for realisation of the selected characters for the designatedelements. This could be via an intermediary that records the customersspecifications for later use and utilises the skills of a range ofcraftspersons to make the required elements and co-ordinates thecollocation of the individual elements for assembly. The device will bedescribed in greater detail below with exemplary materials being givenfor specific elements of the device. Where a material or veneer isdiscussed in relation to an element, the reader should be aware that theparticular character of the element described is one of many or severalthat may be provided as options to a party commissioning a personaliseddevice. In addition the exact material or surface decoration of theelement could be individually commissioned. As another option thespecification of the commissioner could be directly forwarded to alocation with the selected elements in stock for immediate assembly. Inthis embodiment either individually commissioned elements would not bepossible at all or restricted to a relatively small number of tasks thatcan be performed after the initial materials and finish of an elementhave been decided, such as engraving and possibly jewel encrustation.

For greater freedom in individually commissioned elements, theseelements could be individually designed and fabricated and finallyforwarded for assembly with the less unique elements. Should assembly ofthe elements require particular skills or for perhaps other reasons theassembly may occur at yet another location.

The formed article is then conveyed to the end user.

Aspects of the invention have been discussed with reference to a radiotelephone function. It will be clear to the skilled man that theseaspects apply equally to other portable communications devicessupporting in addition or as an alternative other functions, such as,amongst others electronic diaries, and electronic notepads.

In the future, although the casing will probably be maintained insubstantially the same condition, the engine could be replaced with anengine that perhaps has greater processing power or allows for differentfunctionality, for example improved graphics. To replace the engine willbe a relatively simple manner of removing the existing engine andreplacing it with a new one. The battery and internal casing walls maybe changed at the same time if greater battery volume is then possible.

The present invention includes any novel feature or combination offeatures disclosed herein either explicitly or any generalisationthereof irrespective of whether or not it relates to the claimedinvention or mitigates any or all of the problems addressed.

In view of the foregoing description it will be evident to a personskilled in the art that various modifications may be made within thescope of the invention.

1. A reusable casing for a personal portable communication device havingan operating face carrying a user interface including a plurality ofuser input elements, the casing comprising: a plurality of housingelements configured to define a cavity for receiving an engine providingthe electronic functionality of the device and a battery for poweringthe engine; attaching elements configured to releasably attach thehousing elements one to another to provide access to the cavity forreceiving the engine; a dividing member configured to define a batterycavity accessible to the user and an engine cavity, the dividing memberaccommodating a connection between the battery and the engine, whereinthe dividing member is replaceable to provide different respectivevolumes for the battery and engine cavities; mounts configured toremovably mount the engine within the engine cavity; and mountsconfigured to removably mount the battery within the battery cavity. 2.A reusable casing according to claim 1 wherein the battery and theengine are displaced along the length of the casing.
 3. A reusablecasing according to claim 1 wherein the design of replacement housingelements configured to receive the engine and battery is dependent uponthe size and shape of a second engine and battery pair.
 4. A reusablecasing according to claim 1 wherein the battery cavity is accessible toa user for replacing a battery.
 5. A reusable casing according to claim1 wherein the user interface comprises a display.
 6. A personal portablecommunication device comprising an engine and a reusable casingaccording to claim
 1. 7. A personal portable communication deviceaccording to claim 6 wherein the casing is provided with externalconnectors allowing for greater capability than is provided for by thefunctionality of the engine.
 8. A personal portable communication deviceaccording to claim 6 wherein at least one of the connectors is free fromsignals.
 9. Use of a casing of a portable communication device having anoperating face carrying a user interface including a plurality of userinput elements, a first removable engine having hardware providing apredetermined processing capability for supporting electronicfunctionality of the device, and a dividing member configured to definea battery cavity and an engine cavity within the portable communicationdevice, the battery cavity being accessible to a user, wherein thedividing member is replaceable to provide different respective volumesfor the battery and engine cavities, the use being for housing a secondengine in place of the first engine, having hardware defining adifferent predetermined processing capability to the first engine suchthat a portable communication device having different operationalcharacteristics is produced.
 10. A method of modifying a portablecommunication device having an operating face carrying a user interfaceincluding a plurality of user input elements, hardware providing apredetermined processing capability for supporting electronicfunctionality of the device, and a dividing member configured to definea battery cavity and an engine cavity within the portable communicationdevice, the battery cavity being accessible to a user, the methodcomprising: removing the engine from the casing; replacing the dividingmember to provide different respective volumes for the battery andengine cavities; and replacing the engine with another engine havinghardware providing a different predetermined processing capability. 11.A kit of parts for a reusable portable communication device comprising:a casing having an operating face carrying a user interface including aplurality of user input elements, the casing defining a cavity forreceiving an engine providing the electronic functionality of the deviceand a battery for powering the engine; and a dividing member configuredto define a battery cavity accessible to the user and an engine cavity,wherein the dividing member is replaceable to provide differentrespective volumes for the battery and engine cavities.
 12. A reusablecasing for a personal portable communication device having an operatingface carrying a user interface including a plurality of user inputelements, the casing comprising: housing elements defining a cavity forreceiving an engine providing the electronic functionality of the deviceand a battery for powering the engine; attaching elements configured toreleasably attach the housing elements one to another to provide accessto the cavity for receiving the engine; a dividing member configured todefine a battery cavity accessible to the user and an engine cavity, thedividing member accommodating a connection between the battery and theengine, wherein the dividing member is replaceable to provide differentrespective volumes for the battery and engine cavities; mountsconfigured to removably mount the engine within the engine cavity; andmounts configured to removably mount the battery within the batterycavity.
 13. A reusable casing for a personal portable communicationdevice having an operating face carrying a user interface including aplurality of user input elements, the casing comprising: housingelements defining a cavity for receiving an engine providing theelectronic functionality of the device and a battery for powering theengine; attaching elements configured to releasably attach the housingelements one to another to provide access to the cavity for receivingthe engine; a dividing member configured to define a battery cavityaccessible to the user and an engine cavity, the dividing memberaccommodating a connection between the battery and the engine, whereinthe dividing member is replaceable to provide different respectivevolumes for the battery and engine cavities; mounts configured toremovably mount the engine within the engine cavity; and mountsconfigured to removably mount the battery within the battery cavity,wherein the battery and the engine are located in different portionsalong the length of the casing.
 14. A reusable casing for a personalportable communication device having an operating face carrying a userinterface including a plurality of user input elements, the casingcomprising: housing elements defining a cavity for receiving an engineproviding the electronic functionality of the device and a cavity forreceiving a battery for powering the engine; attaching elementsconfigured to releasably attach the housing elements to one another toprovide access to the cavity for receiving the engine; a dividing memberconfigured to define a battery cavity accessible to the user and anengine cavity, wherein the dividing member is replaceable to providedifferent respective volumes for the battery and engine cavities; andmounts configured to removably mount the battery within the batterycavity and mounts configured to removably mount the engine within theengine cavity.
 15. A reusable casing according to claim 14, wherein thehousing elements defining the engine cavity permit placement of engineswith predetermined processing capabilities that are different.
 16. Areusable casing for a personal portable communication device having anoperating face carrying a user interface including a plurality of userinput elements, the casing comprising: means for defining a cavity forreceiving an engine providing the electronic functionality of the deviceand a battery for powering the engine; means for releasably attachingthe means for defining a cavity one to another to provide access to thecavity for receiving the engine; dividing means for defining a batterycavity accessible to the user and an engine cavity, the dividing meansaccommodating a connection between the battery and the engine, whereinthe dividing means is replaceable to provide different respectivevolumes for the battery and engine cavities; mounting means forremovably mounting the engine within the engine cavity; and mountingmeans for removably mounting the battery within the battery cavity.